This invention relates generally to processes for peeling fresh citrus fruit and, more particularly, to such processes that utilize the infusion of a pectinase enzyme into the fruit.
An example of a pectinase enzyme-infusion process of this particular kind is described in U.S. Pat. No. 4,284,651 to Bruemmer. In the described process, washed citrus fruit such as oranges and grapefruit are initially heated to a surface temperature of about 40 to 60 degrees C. and a core temperature of about 20 to 40 degrees C., after which the peel surface of the fruit is scored so as to penetrate the fruit's albedo or white layer, but not penetrate the fruit's juice segments. An aqueous solution of a pectinase enzyme is then vacuum infused into the fruit's albedo, at a vacuum of about 25 to 30 inches of mercury. After incubating the fruit for a period of 15 minutes to two hours, at a temperature of about 30 to 60 degrees C., the peel and other membrane material is removed from the fruit and the exposed fruit segments are separated from each other, with most of the segment membranes remaining intact. The fruit segments can then be refrigerated for extended durations, while retaining a fresh fruit flavor and appearance.
Although the process described briefly above has proven to be generally satisfactory in providing individual fruit segments having a fresh fruit flavor and appearance, it is believed that the process can be improved upon in several respects. For example, it is believed that a still higher proportion of individual fruit segments can be separated without damaging the segment's membrane and with less adhered albedo. In addition, it is believed that the pectinase enzyme solution used in the process can be used in a way that reduces its tendency to rapidly break down and lose its effectiveness so that it can be used effectively with more than just a single batch of citrus fruit.
It should, therefore, be appreciated that there is a need for an improved process for enzyme peeling fresh citrus fruit, which is effective in providing a increased ease in peeling and reduced adhering albedo and which can utilize a particular batch of pectinase enzyme solution to process a greater number of fresh fruit. The present invention fulfills this need.